Best ever summation of how this tool got re-elected. Short answer is that the local GOP is Teh Suck:
In
2006, Judy Barr was the last remaining Republican constitutional
officer in Illinois (Illinois State Treasurer, 1998-2006) when she
decided to roll the dice and run for governor. Unfortunately, her years
as a more-or-less moderate Republican meant that the whackjob wing of
the Illinois GOP (also known as “The Illinois GOP”) made sure she came
out of the party primary extra-heavily bloodied, and then had to stand
up a statewide campaign against an incumbent governor whose now-famous
Awesome Shakedown Powers meant he could build a 27 million dollar war
chest.
She got crushed.
A.

Drifty’s got some great Chi-town insights on these people.
While I can understand why that might make it hard for a GOP candidate to win, I’m not sure that’s a good excuse for why the Democratic machine in Illinois can’t clean up its own act. You really can’t blame the GOP for not winning against corrupt candidates.